Work on default theme.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
More work on default theme.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
UI Changes:
- Added default UI theme to gameplay/res/ui, which is copied into sample folders.
- Optimized UI layout code (still in progress).
- Removed AUTO_SIZE_STRETCH in favor of width=100% and height=100%.
- Changed all controls to default to autoSize=AUTO_SIZE_BOTH, which automatically sizes controls to tightly fit their contents. This greatly simplifies UI creation since explicit sizes are no longer required.
- Updated samples to reflect the above mentioned changes to auto-sizing.
- Cleaned up a lot of UI code (still more to do).
- Updated lua bindings.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next

Conflicts:
	gameplay/gameplay.vcxproj
	gameplay/gameplay.vcxproj.filters
	gameplay/src/lua/lua_Joystick.h
	gameplay/src/lua/lua_JoystickControl.cpp
Layout optimizations continued.
More UI layout optimizations.
UI layout optimizations.
Updated UI controls to track dirty state in such a way that layouts should no longer occur every frame. Layout should now only happen when a control is resized or some other property affecting layout changes.
For optimization purposes, UI now determines layout and auto-sizing based on the NORMAL UI/input state. This means that you cannot have a hover or active state for a UI control that changes the size of the control.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Merge pull request #1420 from sgrenier/next

UI theme and layout changes